This invention relates to photocurable or actinic light curable epoxy-containing compositions. More particularly it relates to epoxy-containing compositions having improved flexibility.
Conventional actinic light cured or photocured epoxy-containing compositions generally have high internal strength and extreme rigidity which makes them ideally suited for most high performance bonding applications. However, for some applications, conventional photocured epoxy-containing compositions have been found to be too rigid or brittle and attempts have been made to reduce their rigidity (i.e., to flexibilize them or to increase their flexibility). Hydroxyl-functional organic materials have been incorporated into photocurable epoxy compositions to reduce their rigidity. The flexibilization of epoxy-containing compositions with hydroxy-functional materials, although satisfactory for many purposes (e.g., coatings), is generally not sufficient for all purposes or applications (e.g., where greatly improved elongation is required).